One known type of a conventional air conditioning apparatus exchanges heat between a refrigerant-side cycle (primary cycle) and a water-side cycle (secondary cycle) and collects condensation heat generated during cooling operation so that heating and cooling can be performed simultaneously.
If heating only operation is performed or if a heating capacity is larger than cooling capacity in the cooling heating simultaneous operation, when an ambient temperature is low, frost is formed on the air heat exchanger. The defrosting capacity for removing the frost is basically determined on the basis of electricity supplied to the compressor. Defrosting operation has been performed under the cooling heating simultaneous operation so as to use neat absorbed from a cooling load as a heat source to increase the defrosting capacity (see PTL 1, or example).